Select "Utilities" and "Terminal" to launch the command console and attempt to format troublesome hard drives that can't be formatted within Mac OS X.

These 20 essential Mac terminal commands allow you to easily navigate the system, manage files, perform system tasks and more.

Terminal brings the command line back to your Mac. Here's how to use it to customise and troubleshoot your Mac, and the most commonly used Terminal commands ...

Once backed up, Restart your Mac and hold down Command-R to enter Recovery Mode in the Mac's firmware. Once Recovery Mode's Utilities window appears, select Utilities->Terminal to launch the Terminal.

The OS X Terminal opens up a world of powerful UNIX utilities and scripts. If you're migrating from Linux, you'll find many familiar commands work t ...

To use OS X's handy OS X Recovery feature, or to enable FileVault on an external drive, you need a special recovery partition on your drive. This utility can add it if the OS X installer didn't.